Switching between Polymer Architectures with Distinct Thermoresponses.
Wenhui Sun1, Zesheng An2, Peiyi Wu1,3
1The State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200433, China.
Macromolecular Rapid Communications
|February 28, 2017
Summary
Researchers achieved reversible switching between linear polymers and cross-linked nanogels. This polymer architecture engineering significantly alters smart polymer thermoresponsive properties, offering distinct thermal transitions for each form.
Area of Science:
- Polymer Chemistry
- Materials Science
- Nanotechnology
Background:
- Thermoresponsive polymers and their nanogels usually share similar thermal behavior.
- Controlling polymer architecture is key to tuning material properties.
Purpose of the Study:
- To demonstrate reversible chemical switching between linear polymers and cross-linked nanogels.
- To investigate how polymer architecture influences thermoresponsive profiles.
Main Methods:
- Synthesis of thermoresponsive linear polymers.
- Chemical cross-linking to form nanogels.
- Thermal transition analysis of both polymer forms.
Main Results:
- Linear polymers showed sharp thermal transitions.
- Cross-linked nanogels exhibited broader, "linear" thermal transitions.
- Successful reversible switching between the two architectures was achieved.
Conclusions:
- Polymer architecture engineering offers a unique method to significantly manipulate the responsive properties of smart polymers.
- Distinct thermoresponses can be obtained by switching between linear and cross-linked nanogel forms.
Related Concept Videos
01:26Polymer Classification: Stereospecificity
3.4K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
3.4K
01:21Polymer Classification: Crystallinity
4.2K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
4.2K
01:14Polymer Classification: Architecture
4.0K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
4.0K
01:24Characteristics and Nomenclature of Copolymers
3.5K
Copolymers are the products obtained from the polymerization of multiple monomer species. So, in a polymer chain itself, there can be multiple repeating units that come from different monomers. The process of synthesizing a polymer from different monomer species is called copolymerization. When two monomers are involved, the polymer is known as a bipolymer. Polymers with three and four monomers are termed terpolymers and quaterpolymers, respectively. Figure 1 depicts the copolymerization of...
3.5K
01:03Step-Growth Polymerization: Overview
4.5K
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
4.5K
02:34Polymers
42.4K
The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the...
42.4K